Government surveillance authorities and commercial data collection have grown alongside digital life. The US has no comprehensive federal privacy law, leaving a patchwork of sectoral rules and state statutes.
Foreign intelligence surveillance authorities permit collection targeting non-citizens abroad, which incidentally captures communications of Americans in contact with them. The rules for querying that incidental collection are a recurring point of dispute.
Commercial data brokers assemble detailed profiles from purchases, location, and browsing. Government agencies have in some cases purchased data they would otherwise need legal process to obtain, which critics describe as a workaround.
Encryption protects communications from interception but limits lawful access even with a warrant. Proposals for guaranteed access face the technical objection that a vulnerability created for one party is available to any party who finds it.